Just for fun, I decided to further my experiments with Exchange by cleaning up the biggest mailbox on the system, my boss’. I took a preliminary reading of the Folder Size. 544MB. Ye-ouch! Then I created a second mailbox, and proceeded to copy all of his messages into the new box. He had a couple dozen personal folders set up, I copied them. He had over a thousand contacts, I copied them. he had 500 Sent Items, I copied them. I recreated his mailbox exactly, with the exact same items. I checked the item counts on every folder to make sure they were identical. I went to the Exchange Administrator program to do a mailbox-wide count of items. 9,758. Identical. Then I looked at the Folder Size on the new mailbox. 377MB.

167 megabytes. In one mailbox, there was 167 megabytes of wasted space. That’s astounding. I guess at this point it doesn’t matter where it all came from. My money is still on that botched defrag. But now I am faced with the task of going through every mailbox and cleaning it up like this. And that doesn’t sound too thrilling. My Exchange database is sitting at 2.3GB right now. It’ll be interesting to see how far it shrinks once I’ve gotten rid of all this garbage.

I couldn’t pull myself away from the desk last night, I was trying to figure through this problem with the Exchange Server. There was all this wasted space coming from somewhere. What I finally did was take one of the affected mailboxes, and check the Folder Size. 46MB. I then created a new mailbox and copied all the items over to it. I copied the whole Inbox, all the Sent Items, Notes, Journal, Contacts, Calendar, everything. I copied it all and looked at the Folder Size of the new mailbox. 23MB.

That’s when my jaw hit the floor. Out of the entire mailbox, half of it was invisible cruft, wasted space. Half of it. I checked the individual folder sizes. The Sent Items had 131 items. Old mailbox, 2.3MB. New mailbox, 0.8MB. This is un-freaking-believable. What is all of this? I might have an idea. I remember that a few months ago I did an offline defragmentation of the Exchange database, and it got corrupted. I tried to restart Exchange after the defrag, and it wouldn’t. It kept throwing errors that, when I looked them up, turned out to be corruption errors. So I threw all the Exchange tools I had at it. I did a repair, I checked the integrity, I defragged it again. Finally I got the server to start, and something like half—or more—of everyone’s e-mails were missing. So I did a restore from the tape backup and called it good. I’ve done a couple more offline defragmentations since then, and they’ve gone without a hitch.

Could that have been it? During one of those repairs, did it mark a bunch of items as unrecoverable, but leave the data drifting loose in space? I guess that would explain all the extra weight in those folders, it’s the items that were lost during the corruption and recovery. But why is the data still taking up space? Why isn’t it swept away during the defrag? How does Exchange handle that sort of thing? And what are my options from this point? Am I to go through all 50 mailboxes, create new boxes, move the items over, and delete the old mailboxes? Do I need to set up a second Exchange Server, replicate everything over, delete everything from the old server, and then replicate back? None of these options sound particularly appealing, but neither does going on with an Exchange database that’s bloated by 200%.

Oh, the joys of being a network admin.